Hi Javier,

On Wed, Sep 04, 2024 at 03:53:40PM +0200, Javier Carrasco wrote:

On 04/09/2024 06:47, Dmitry Torokhov wrote:

quoted

Using guard notation makes the code more compact and error handling
more robust by ensuring that mutexes are released in all code paths
when control leaves critical section.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/misc/iqs269a.c | 46 +++++++++++++-----------------------
 1 file changed, 16 insertions(+), 30 deletions(-)

diff --git a/drivers/input/misc/iqs269a.c b/drivers/input/misc/iqs269a.c
index 843f8a3f3410..c34d847fa4af 100644
--- a/drivers/input/misc/iqs269a.c
+++ b/drivers/input/misc/iqs269a.c

...

quoted

@@ -453,9 +449,9 @@ static int iqs269_ati_base_get(struct iqs269_private *iqs269,
 	if (ch_num >= IQS269_NUM_CH)
 		return -EINVAL;
 
-	mutex_lock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);
+
 	engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);

maybe scoped_guard() to keep the scope of the mutex as it used to be?

Thank you for looking over patches.

It is just a few computations extra, so I decided not to use
scoped_guard(). Note that original code was forced to release mutex
early to avoid having to unlock it in all switch branches.

quoted

-	mutex_unlock(&iqs269->lock);
 
 	switch (engine_b & IQS269_CHx_ENG_B_ATI_BASE_MASK) {
 	case IQS269_CHx_ENG_B_ATI_BASE_75:

@@ -491,7 +487,7 @@ static int iqs269_ati_target_set(struct iqs269_private *iqs269,
 	if (target > IQS269_CHx_ENG_B_ATI_TARGET_MAX)
 		return -EINVAL;
 
-	mutex_lock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);
 
 	engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
 

@@ -501,8 +497,6 @@ static int iqs269_ati_target_set(struct iqs269_private *iqs269,
 	ch_reg[ch_num].engine_b = cpu_to_be16(engine_b);
 	iqs269->ati_current = false;
 
-	mutex_unlock(&iqs269->lock);
-
 	return 0;
 }
 

@@ -515,10 +509,9 @@ static int iqs269_ati_target_get(struct iqs269_private *iqs269,
 	if (ch_num >= IQS269_NUM_CH)
 		return -EINVAL;
 
-	mutex_lock(&iqs269->lock);
-	engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
-	mutex_unlock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);

same here?

quoted

 
+	engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
 	*target = (engine_b & IQS269_CHx_ENG_B_ATI_TARGET_MASK) * 32;

Same here, calculating the line above will take no time at all...

Thanks.

-- 
Dmitry